I suspect your problem is going to be the efficiency quoted for the microwave - efficient at doing what?
Microwave ovens are reasonably efficient at generating microwaves (i.e. the electrical power used vs the microwave energy output of the magnatron) but that doesn't mean using 1100W of microwave output is an efficient way to heat a cup of water. My own microwave draws about 8.35A of power for its advertised 1100W of output, but it will pull that same amount of power if it's empty or "full".
Perhaps the only practical way to compare microwave to kettle would be to meter the current draw for set time (say 2 mins) measure temperature rise of a cup of cold water in the microwave and the kettle (or the minimum cold water allowed by the kettle) ...then do the numbers of energy used by the device and joules required to raise the temp difference measured for the volume of water. I'd be surprised if a high-powered microwave is more efficient at doing that task even if you need to boil a min of 3 cups of water in the kettle.
And FWIW: My microwave appears to draw 0.35A doing nothing... my kettle kicks it's arse on that one.

Interesting fact (for those who don't know) the typical smoke detector is 'nuclear powered' - using a small amount of radioactive Americium-241 and a comparative circuit, to detect the difference in ionizing radiation received by an electrode in sealed and unsealed chambers - very clever tech we just take for granted.

Assuming the same amount of water... I would think kettle. All of its energy is directed at the water, and it switches off when boiling, whereas the microwave blasts energy all over the place (including outside) runs a turntable, clock/timer/etc and has no idea when the water is boiling.

Yep, that's where we agree.
As an atheist, I don't believe there is a "point" to life per-se, but that's not the same as believing life has no value as a consequence.
I disagree with religion, am surprised it survives in educated communities, and am dismayed that so much harm has been caused in the name of various religions.
However, I still believe that each individual has the right to live their life as they wish and believe what they wish, even if I disagree with it and might argue over the logic of it, provided they don't deny the same rights to others.
And for those who won't accept those basic constraints of community and decency, we have a rule of law to provide boundaries.

Oh, FFS... how is that different to Scientology BS we all scoff at?
Religion is just a desperate childish attempt to deal with the scary fact that you are going to die.
I really struggle to understand how otherwise sensible people can base their very short lives around fairy-tales. I think it should be one of the section-44 exclusion conditions for being a member of parliament.
Personally, I'm not scared of dying, because I won't know anything about it - I'll be dead.